Ian Baker¹; ¹Dartmouth College

The microstructures of directionally-recrystallized, cold-rolled polycrystalline nickel have been investigated using both EBSPs on a SEM and optical microscopy. The effects of the process parameters (hot zone velocity, hot zone temperature and temperature gradient ahead of the hot zone) and microstructural parameters (solute, particles) on the microstructure produced by directional annealing will be outlined. Columnar grains and single crystals could be produced by secondary recrystallization following primary recrystallization over a wide range of hot zone velocities, but only at high temperature (≥1100K) with a large temperature gradient. The effects of solutes and particles was to move the processing window to higher temperatures and lower hot zone velocities. The results of simulations of directional recrystallization using a front-tracking model will also be presented for both particle-free and particle-containing material, and compared to experimental observations. This research is currently supported by the U.S. Army Research Office grant W911NF-16-1-0367.